Project M3: Part 3 – Headers, software, dyno testing and more!

100whp per liter or bust!

by Pablo Mazlumian

This project is starting to get really fun.  Building an E46 M3 is reminiscent of building cars in a Gran Turismo video game.  Every little modification seems to release a little more power. 

When we started, the car dyno’d a respectable 290whp on Modified by KC’s Dynojet 248C.  After a fluids flush, new plugs, stock-box intake, software tune, pulleys and cat-back exhaust, we’re up to over 307whp.  Our goal now is to reach the holy grail of specific output—100 wheel horsepower per liter—a feat in the O.E. world done only by big-dollar exotics such as the Ferrari 430 16M, Ferrari 458 and Porsche GT3/GT3 RS.  Yes, their displacement is bigger, making their achievement even more impressive, but doing it with 3.2 liters would still be sweet.


We’ll be testing Fabspeed headers sold exclusively by VAC Motorsports.  We sent these units to Swain Tech for their “White Lightning” treatment.  Check out the video at the end of this article showing the sound differences between stock, with cat-back and then with full exhaust.



An ECU reflash will be necessary when catalytic converters are removed.  Our previous tune in Part 1 came from Randy Mueller at Epic Motorsports.  He’s known to be one of the best in the business and has not disappointed thus far.  We’re working with him again today.



In anticipation of the extra power, we want to ensure optimal spark.  I've tested Bavarian Autosport’s high performance ignition coils previously on a modified E36 M3, and hope to see similar results today.



Lastly, to prevent oil build up in the intake manifold, which will keep our fuel's octane optimal, we’ll be installing a nifty catch can setup from Radium Engineering.
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Tuesday, October 01, 2013 8:38 AM
Not really a fanboy, but:

100 hp / liter is only for high dollar exotics?
The 1999 Honda S2000 begs to differ, 120hp/liter.
Heck, even the plebian Civic Si was 98.5hp/L and over the 100hp? Liter with just an air filter...

Amazing achievements.. now if only either of those motors were 5 or 6 liters of displacment!
Pablo Mazlumian
Pablo Mazlumianlink
Tuesday, October 01, 2013 9:17 AM
Hi, thank you for reading. We're talking a no-boost WHEEL hp/liter, not OE-spec "bhp". If we talked the latter, we'd have to mention E30/E36 M3 evo's, E46/E92 M3s, E60 M5, Carrera S/GT3/GT3 RS, McLaren F1, LF-A, Audi RS4/R8/Lambo Gallardo, all the Ferraris made after (and including) the '95 F355, BRZ/FR-S, ITR, etc etc. But that's not 100 WHP/liter. Also, a stock S2000 does not dyno 200whp. A modified one would, sure, along with an Integra TypeR (and then we can go to smaller engined crotch rockets, which have even a greater specific output, too).

However, as mentioned in Part 1, with 100whp/liter we're discussing larger motors because it's harder to accomplish this the larger the cylinders get (more tensile load at the rods with the much needed, and relatively very high RPM). So, absolutely not to take anything away from crotch rocket motors or an S2K/ITR (I've tracked both cars and absolutely love them! Best trannies ever, too), but we're talking 100whp/liter motors that also make good torque.
Tuesday, October 01, 2013 1:36 PM
Nice writeup and congrats on the results.

Any comment on emissions legality of the headers and catch can in your state? Are these parts covered under a CARB EO? Just curious.
Dan DeRosia
Dan DeRosialink
Tuesday, October 01, 2013 4:14 PM
The RX-8 makes 185ish at the rear wheels stock, which given 1.3L is well over 100hp/L! (I know I know, rotaries don't count)

Seriously though, kinda cool. Wouldn't have thought there'd be that easy of horsepower in an M3.
b drecksage
b drecksagelink
Tuesday, October 01, 2013 5:21 PM
That easy of hp? How much do all of these power mods cost? 4 to 5k for 20hp? I love the e46 m3, but if I were to ever buy them...I would not be spending that kind of money on such a small gain.

On the flip side... I appreciate this article and info...its a good read. Thanks
Dan DeRosia
Dan DeRosialink
Wednesday, October 02, 2013 4:11 AM
Yeah, for what started out as a pretty highly tuned NA engine, that's easy horsepower; this isn't some turbo motor where you can just crank more boost into it, and it's German so yeah, parts are going to cost more. I would have been really skeptical if you'd told me that there was 30whp waiting in bolt-ons.
Wednesday, October 02, 2013 6:59 AM
Torque and S2000 don't belong in the same sentence :) The 2.0L AP1 engine typically puts down around 190-195whp stock on a dynojet. The 2.2L AP2 (2.16L to be more accurate) will put down around 200whp stock. It's very hard to extract power out of them which is why I haven't really done much to Project S2000 in the power department. Intake, headers, test pipe, and exhaust will only get you to around 230whp.
Wednesday, October 02, 2013 7:20 AM
Nice power gains, but I still hear the terrible rasp (moreso, in fact). I've heard a V8 M3, and it sounds like heaven. E46 M3, not so much. :)

Even still, the E46 M3 is probably the best value performance/dollar in the BMW world right now. New BMWs are WAY too costly.
Pablo Mazlumian
Pablo Mazlumianlink
Wednesday, October 02, 2013 10:54 AM
Thanks for reading, y'all. To answer some questions:

-@CFLO-thank you much. Taking out cats is for "off road use" only, as mentioned in Page5. However, VAC/Fabspeed does offer a cat option, which will only cost a reported 4-5whp. EPIC also has a tune for this.

-@b dreksage-as Dan mentioned, getting significant gains from an already high-strung car is not the same as something with a low specific output, like a Mustang GT. And "small", as you know, is a relative term.
In this case, many would agree that $3850+shipping/install for headers, exhaust, intake, software, pulleys that are good for nearly 40whp gains on an M3 is very good for no boost, and we're talking 14% power gains--that's quite a bit. Shoot, you could even keep the stock cat-back section, which will cost you 3-4whp but make you back $1600. Today's 16whp (going from 307-323whp but with a peak 24whp gain) was only $1250+install for the headers (you'll only pay for a tune once if you plan it correctly). And the first 20whp peak gain in part one was only around $800 (Epic tune/MS intake)!

-@Spdracrut-I'd take a nice, clean 230whp NA 2.2L S2000 ANY DAY (so long it doesn't sound like a loud fart can). that would be a fun weekend toy.

-@Rockwood-with the Corsa exhaust on there alone, it sounds awesome. You really get a sense of it in the vid with the black M3, which is in my family as well. But yes it will never sound like the V8, ;). Although I am working on tuning the sound a bit more, while also quieting this sucker down. It was on the dyno more today and, my goodness, I had to have my ears plugged during each pull, lol.

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